scholarly journals Morphology of lateral roots of twelve rice cultivars of Bangladesh: dimension increase and diameter reduction in progressive root branching at the vegetative stage

Plant Root ◽  
2015 ◽  
Vol 9 (0) ◽  
pp. 34-42 ◽  
Author(s):  
Arif Hasan Khan Robin ◽  
Parth Sarothi Saha
Keyword(s):  
Lateral Roots ◽  
Vegetative Stage ◽  
Rice Cultivars ◽  
Root Branching ◽  
Diameter Reduction

scholarly journals Effects of Phosphate Shortage on Root Growth and Hormone Content of Barley Depend on Capacity of the Roots to Accumulate ABA

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1722
Author(s):  
Lidiya Vysotskaya ◽  
Guzel Akhiyarova ◽  
Arina Feoktistova ◽  
Zarina Akhtyamova ◽  
Alla Korobova ◽  
...  
Keyword(s):  
Root Growth ◽  
Lateral Roots ◽  
Primary Root ◽  
Growth Responses ◽  
Root Tips ◽  
P Deficiency ◽  
Root Branching ◽  
Auxin Concentration ◽  
Shoot Mass ◽  
Primary Root Length

Although changes in root architecture in response to the environment can optimize mineral and water nutrient uptake, mechanisms regulating these changes are not well-understood. We investigated whether P deprivation effects on root development are mediated by abscisic acid (ABA) and its interactions with other hormones. The ABA-deficient barley mutant Az34 and its wild-type (WT) were grown in P-deprived and P-replete conditions, and hormones were measured in whole roots and root tips. Although P deprivation decreased growth in shoot mass similarly in both genotypes, only the WT increased primary root length and number of lateral roots. The effect was accompanied by ABA accumulation in root tips, a response not seen in Az34. Increased ABA in P-deprived WT was accompanied by decreased concentrations of cytokinin, an inhibitor of root extension. Furthermore, P-deficiency in the WT increased auxin concentration in whole root systems in association with increased root branching. In the ABA-deficient mutant, P-starvation failed to stimulate root elongation or promote branching, and there was no decline in cytokinin and no increase in auxin. The results demonstrate ABA’s ability to mediate in root growth responses to P starvation in barley, an effect linked to its effects on cytokinin and auxin concentrations.

scholarly journals Repression of early lateral root initiation events by transient water deficit in barley and maize

2012 ◽  
Vol 367 (1595) ◽  
pp. 1534-1541 ◽  
Author(s):  
Aurélie Babé ◽  
Tristan Lavigne ◽  
Jean-Philippe Séverin ◽  
Kerstin A. Nagel ◽  
Achim Walter ◽  
...  
Keyword(s):  
Water Deficit ◽  
Developmental Plasticity ◽  
Lateral Roots ◽  
Time Lapse ◽  
Root System Architecture ◽  
Negative Control ◽  
Root Branching ◽  
Branching Patterns ◽  
Primary Determinant ◽  
Key Driver

The formation of lateral roots (LRs) is a key driver of root system architecture and developmental plasticity. The first stage of LR formation, which leads to the acquisition of founder cell identity in the pericycle, is the primary determinant of root branching patterns. The fact that initiation events occur asynchronously in a very small number of cells inside the parent root has been a major difficulty in the study of the molecular regulation of branching patterns. Inducible systems that trigger synchronous lateral formation at predictable sites have proven extremely valuable in Arabidopsis to decipher the first steps of LR formation. Here, we present a LR repression system for cereals that relies on a transient water-deficit treatment, which blocks LR initiation before the first formative divisions. Using a time-lapse approach, we analysed the dynamics of this repression along growing roots and were able to show that it targets a very narrow developmental window of the initiation process. Interestingly, the repression can be exploited to obtain negative control root samples where LR initiation is absent. This system could be instrumental in the analysis of the molecular basis of drought-responsive as well as intrinsic pathways of LR formation in cereals.

scholarly journals Shoot-derived miR2111 controls legume root and nodule development

2020 ◽  
Author(s):  
Mengbai Zhang ◽  
Huanan Su ◽  
Peter M. Gresshoff ◽  
Brett J. Ferguson
Keyword(s):  
Lateral Root ◽  
Lateral Roots ◽  
Ectopic Expression ◽  
Root System Architecture ◽  
Negative Regulator ◽  
Nodule Development ◽  
Wild Type ◽  
Root Branching ◽  
Autoregulation Of Nodulation ◽  
Cle Peptide

AbstractLegumes control their nodule numbers through the Autoregulation Of Nodulation (AON). Rhizobia infection stimulates the production of root-derived CLE peptide hormones that are translocated to the shoot where they regulate a new signal. We used soybean to demonstrate that this shoot-derived signal is miR2111, which is transported via phloem to the root where it targets transcripts of Too Much Love (TML), a negative regulator of nodulation. Shoot perception of rhizobia-induced CLE peptides suppresses miR2111 expression, resulting in TML accumulation in roots and subsequent inhibition of nodule organogenesis. Feeding synthetic mature miR2111 via the petiole increased nodule numbers per plant. Likewise, elevating miR2111 availability by over-expression promoted nodulation, while target mimicry of TML induced the opposite effect on nodule development in wild-type plants and alleviated the supernodulating and stunted root growth phenotypes of AON-defective mutants. Additionally, in non-nodulating wild-type plants, ectopic expression of miR2111 significantly enhanced lateral root emergence with a decrease in lateral root length and average root diameter. In contrast, hairy roots constitutively expressing the target mimic construct exhibited reduced lateral root density. Overall, these findings demonstrate that miR2111 is both the critical shoot-to-root factor that positively regulates root nodule development, and also acts to shape root system architecture via orchestrating the degree of root branching, as well as the length and thickness of lateral roots.

scholarly journals Selection of local swamp rice cultivars from Kalimantan (Indonesia) tolerant to iron stress during vegetative stage

2020 ◽  
Vol 21 (12) ◽  
Author(s):  
Vina Novianti ◽  
Didik Indradewa ◽  
Maryani MARYANI ◽  
Diah Rachmawati
Keyword(s):  
Leaf Length ◽  
Iron Toxicity ◽  
Vegetative Stage ◽  
Enzyme Analysis ◽  
Percentage Increase ◽  
Rice Cultivars ◽  
Iron Stress ◽  
Potential Region ◽  
Biochemical Component ◽  
Selection Of

Abstract. Novianti V, Indradewa D, Maryani, Rachmawati D. 2020. Selection of local swamp rice cultivars from Kalimantan (Indonesia) tolerant to iron stress during vegetative stage. Biodiversitas 21: 5595-5606. Kalimantan with the large swamp area is a potential region in Indonesia to develop local rice cultivars with high tolerance to iron toxicity in tidal lowlands. This research was conducted to select iron toxicity-tolerant in local Kalimantan-rice cultivars, namely: Amas (AMS), Pandan Ungu (PDU), Kambang (KMB), Suatek Merah (SM), Siam Unus Mayang (SUM), Siam Unus Kuning (SUK), and Siam 11 Panjang (S11P). As control, two rice cultivars: Ciherang (iron toxicity-susceptible) and Inpara 5 (iron toxicity-tolerant) were also used. The seeds were grown hydroponically for 35 DAP (days after planting) in Yoshida nutrient solution containing 0 ppm (control), 100 ppm (low), and 400 ppm (high) FeS2 as pyrite treatments. Morphological analysis (plant height, leaf length and width, and leaves number) showed that PDU and KMB cultivars have better characters for tolerating iron toxicity. The highest level of chlorophyll and carotenoid contents during iron toxicity treatment was observed in KMB cultivar. AMS cultivar had the highest proline level under high iron stress. Antioxidant enzyme analysis showed that AMS, PDU, and KMB cultivars had a high percentage increase in the activity of superoxide dismutase (SOD), hydrogen peroxide (H2O2), and ascorbate peroxidase (APX) enzymes when exposed to high pyrite conditions. Based on morphophysiological characteristics, biochemical component, and enzymatic antioxidant activity, it can be concluded that AMS, PDU, and KMB cultivars are potential candidates as iron toxicity-tolerant rice.

scholarly journals Involvement of a truncated MADS-box transcription factor ZmTMM1 in root nitrate foraging

2020 ◽  
Vol 71 (15) ◽  
pp. 4547-4561
Author(s):  
Ying Liu ◽  
Zhongtao Jia ◽  
Xuelian Li ◽  
Zhangkui Wang ◽  
Fanjun Chen ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Lateral Root ◽  
Lateral Roots ◽  
Morphological Plasticity ◽  
Underlying Mechanism ◽  
Grass Species ◽  
Mads Box ◽  
Genetic Redundancy ◽  
Root Branching ◽  
Lateral Root Development

Abstract Plants can develop root systems with distinct anatomical features and morphological plasticity to forage nutrients distributed heterogeneously in soils. Lateral root proliferation is a typical nutrient-foraging response to a local supply of nitrate, which has been investigated across many plant species. However, the underlying mechanism in maize roots remains largely unknown. Here, we report on identification of a maize truncated MIKC-type MADS-box transcription factor (ZmTMM1) lacking K- and C-domains, expressed preferentially in the lateral root branching zone and induced by the localized supply of nitrate. ZmTMM1 belongs to the AGL17-like MADS-box transcription factor family that contains orthologs of ANR1, a key regulator for root nitrate foraging in Arabidopsis. Ectopic overexpression of ZmTMM1 recovers the defective growth of lateral roots in the Arabidopsis anr1 agl21 double mutant. The local activation of glucocorticoid receptor fusion proteins for ZmTMM1 and an artificially truncated form of AtANR1 without the K- and C-domains stimulates the lateral root growth of the Arabidopsis anr1 agl21 mutant, providing evidence that ZmTMM1 encodes a functional MADS-box that modulates lateral root development. However, no phenotype was observed in ZmTMM1-RNAi transgenic maize lines, suggesting a possible genetic redundancy of ZmTMM1 with other AGL17-like genes in maize. A comparative genome analysis further suggests that a nitrate-inducible transcriptional regulation is probably conserved in both truncated and non-truncated forms of ZmTMM1-like MADS-box transcription factors found in grass species.

scholarly journals Growth is required for perception of water availability to pattern root branches in plants

2018 ◽  
Vol 115 (4) ◽  
pp. E822-E831 ◽  
Author(s):  
Neil E. Robbins ◽  
José R. Dinneny
Keyword(s):  
Water Potential ◽  
Water Availability ◽  
Water Movement ◽  
Lateral Roots ◽  
Growth Zone ◽  
High Water ◽  
Developmental Competence ◽  
Root Tip ◽  
Root Branching ◽  
Lateral Branches

Water availability is a potent regulator of plant development and induces root branching through a process termed hydropatterning. Hydropatterning enables roots to position lateral branches toward regions of high water availability, such as wet soil or agar media, while preventing their emergence where water is less available, such as in air. The mechanism by which roots perceive the spatial distribution of water during hydropatterning is unknown. Using primary roots of Zea mays (maize) we reveal that developmental competence for hydropatterning is limited to the growth zone of the root tip. Past work has shown that growth generates gradients in water potential across an organ when asymmetries exist in the distribution of available water. Using mathematical modeling, we predict that substantial growth-sustained water potential gradients are also generated in the hydropatterning competent zone and that such biophysical cues inform the patterning of lateral roots. Using diverse chemical and environmental treatments we experimentally demonstrate that growth is necessary for normal hydropatterning of lateral roots. Transcriptomic characterization of the local response of tissues to a moist surface or air revealed extensive regulation of signaling and physiological pathways, some of which we show are growth-dependent. Our work supports a “sense-by-growth” mechanism governing hydropatterning, by which water availability cues are rendered interpretable through growth-sustained water movement.

scholarly journals Unveiling Endophytic Bacterial Community Structures of Different Rice Cultivars Grown in a Cadmium-Contaminated Paddy Field

2021 ◽  
Vol 12 ◽  
Author(s):  
Chaoqun Chu ◽  
Meiyu Fan ◽  
Chongyang Song ◽  
Ni Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Paddy Field ◽  
Bacterial Communities ◽  
Endophytic Bacteria ◽  
Reproductive Stage ◽  
Vegetative Stage ◽  
Rrna Gene ◽  
Rice Cultivars ◽  
Cd Stress ◽  
Bacterial Phyla ◽  
Rice Roots

Endophytic bacteria play potentially important roles in the processes of plant adaptation to the environment. Understanding the composition and dynamics of endophytic bacterial communities under heavy metal (HM) stress can reveal their impacts on host development and stress tolerance. In this study, we investigated root endophytic bacterial communities of different rice cultivars grown in a cadmium (Cd)-contaminated paddy field. These rice cultivars are classified into low (RBQ, 728B, and NX1B) and high (BB and S95B) levels of Cd-accumulating capacity. Our metagenomic analysis targeting 16S rRNA gene sequence data reveals that Proteobacteria, Firmicutes, Actinobacteria, Acidobacteria, Bacteroidetes, and Spirochaetes are predominant root endophytic bacterial phyla of the five rice cultivars that we studied. Principal coordinate analysis shows that the developmental stage of rice governs a larger source of variation in the bacterial communities compared to that of any specific rice cultivar or of the root Cd content. Endophytic bacterial communities during the reproductive stage of rice form a more highly interconnected network and exhibit higher operational taxonomic unit numbers, diversities, and abundance than those during the vegetative stage. Forty-five genera are significantly correlated with Cd content in rice root, notably including positive-correlating Geobacter and Haliangium; and negative-correlating Pseudomonas and Streptacidiphilus. Furthermore, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States analysis shows that functional pathways, such as biosynthesis of siderophore and type II polyketide products, are significantly enhanced during the reproductive stage compared to those during the vegetative stage under Cd stress. The isolated endophytic bacteria from the Cd-contaminated rice roots display high Cd resistance and multiple traits that may promote plant growth, suggesting their potential application in alleviating HM stress on plants. This study describes in detail for the first time the assemblage of the bacterial endophytomes of rice roots under Cd stress and may provide insights into the interactions among endophytes, plants, and HM contamination.

scholarly journals Selection of drought-tolerant local rice cultivars from East Nusa Tenggara, Indonesia during vegetative stage

2019 ◽  
Vol 21 (1) ◽  
Author(s):  
Yustina Carolina Febrianti Salsinha ◽  
Didik Indradewa ◽  
Yekti Asih Purwestri ◽  
Diah Rachmawati
Keyword(s):  
Intercellular Co2 Concentration ◽  
Stability Index ◽  
High Sensitivity ◽  
Co2 Concentration ◽  
Vegetative Stage ◽  
Severe Drought ◽  
Rice Cultivars ◽  
Drought Tolerant ◽  
Physiological Analysis ◽  
Selection Of

Abstract. Salsinha Y C F, Indradewa D, Purwestri Y A, Rachmawati D. 2020. Selection of drought-tolerant local rice cultivars from East Nusa Tenggara during vegetative stage. Biodiversitas 21: 170-178. East Nusa Tenggara (NTT), with the predominance of dry climate, has the potential of the plant with high tolerance to drought. This research was conducted to select drought-tolerant rice cultivars. There were eight NTT-rice cultivars tested: Pak morin (P1), Mapan (P2), Pak Mutin (P3), Gogo Fatuhao (P4), Seratus-malam Boawae (P5), Padi-Putih Kuatnana (P6), Padi-Putih Maumere (P7) and Gogo Sikka (P8) with 2 control cultivars tested: Ciherang (drought- susceptible) and IR-64 (drought tolerant). The treatment included were 100% FC (control), 50% FC (moderate) and 25% FC (severe drought) during vegetative stage. The morphological analysis of plant (plant height, number of leaves and tillers and root architecture) showed cultivars P1, P5 and P6 possess the best characteristics for tolerating drought. The physiological analysis (plant photosynthetic rate, stomatal conductance, intercellular CO2-concentration, and transpiration rate) showed cultivar P5 and P6 possess the best characteristics for tolerating drought. The high levels of chlorophyll and carotenoid contents during drought conditions were observed in P5, P6, and P7 cultivars. Based on the relative water content, membrane stability index and proline levels, highest-resistance cultivar was P5 and P7 while the cultivar with high sensitivity to drought stress was P3. Based on the morphophysiological characteristics, it can be concluded that P5, P6, and P7 cultivar have the potential as drought-tolerant rice.

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